Extension-ladder.



No. 843,204. PATENTED FEB. 5, 1907. J. R. GODDARD.

EXTENSION LADDER.

APPLICATION FILED NOV. 20, 1906.

- L Inward/0r fimu Y/MMM WM Q g m k UNITED STATES PATENT OFFICE.

JAMES R. GODDARD, OF NEW BEDFORD, MASSACHUSETTS.

EXTENSION-LADDER.

Specification of Letters Patent. Application filed November 20, 1906. Serial No. 344,343.

No. 843,204. Patented Feb. 5, 1907.

To all whom it may concern: their ends secured to the drum d and pass- Be it known that 1, JAMES R. GODDARD, a i ing over the pulleys q g, which are secured to citizen of the United States, residing at New 1 the outer end of the primary ladder a. The Bedford, in the county of Bristol and State opposite ends of said ropes are secured to of Massachusetts, have invented certain new the inner end of the extension-ladder b at r r. and useful Improvements in Extension-Lad 1 The operation of the device is as follows: ders, of which the following is a specification. The tank at is charged with compressed air through the inlet-pipe p, having valve 19.

The object of my invention is to provide an extension-ladder capable of being ex- The valve n being closed, the valve 7c is tended to its full length within a few seconds opened and the force exerted by the comof time and carrying with it at the same time pressed air in tanki allowed to operate on the one or more men, together with fire-hose, and i piston-heads h to drive them to the opposite still be under the perfect control of the opends of the cylinders e e, which motion, erator to retract or extend to any desired inthrough the racks g and gears c, revolves the termediate point or degree. drum d and winds the ropes :0 upon it, thereby To this end my invention consists in proi extending the ladder b to any desired height viding means whereby the extension part of which it is adapted to attain. To lower the said ladder is extended by the force of comladder b, the valve 7c is closed and the valve ressed air, the construction and operation of n opened, thereby allowing the force of which means is illustrated in the accompanycompressed air exerted on the under side of ing drawings, inwhich the piston-heads h to escape, thus causing Figure 1 is a side view of an extension-ladthe ladder b to descend to its normal or any der provided with my improvements. Fig. desired point by its own weight.

2 is a front view of the same, and Fig. 3 is a By means of my improvements the ladder view of some of the detail. b can be extended to its full capacity while Similar letters refer to similar parts in the carrying one or more men, together with fireseveral views. i hose, within a few seconds of time.

The letter (1 represents the primary ladder, l and 1) represents the secondary or extension ladder. The primary ladder a is provided with cylinders e e, secured to its base and v Having thus described my invention, what connected with a receiver or air-tank 't. The

7r, hav- I claim, and desire to secure by Letters Patent, is

An extension-ladder, provided with a cylinder, or cylinders connected with a receiver or tank through which the force of compressed air is adapted to be exerted on the heads of pistons in said cylinders; means whereby the motion of said pistons is caused to revolve a drum journaled on said ladder; a rope, adapted to be wound upon said drum, having one end secured to the ladder to be extended; whereby when the force of compressed air is exerted in the cylinders, the extension portion of said ladder is extended.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES R. GODDARD.

tank '6 is provided with an outlet-pipe ing the valve 7c, and is connected with the ipe l l, which pipe is connected with the ottoms of the cylinders e e. The pipe Z Z is provided with the escape-pipe n, having a valve n The cylinders e e are provided with racks or pistons g, having their lower ends provided with piston-heads h, as shown in Fig. 3.

To about the center of the primary ladder a is journaled the drum (1, having secured to the ends of its shaft the spur-gears c c, which are adapted to mesh with the racks g g.

s 8 represent flanged rollers journaled to l the sides of the primary ladder, which serve l to hold the racks g in contact with the gears c and also as guides for said racks or pistons. i

having one of Witnesses:

J. B. SMITH,

a: :1; represent; wire ropes, HENRY W. MASON. 

